Raspberry Pi 4 WiFi signal can interfere with high resolutions via HDMI

The Raspberry Pi 4’s Wi-Fi signal may interfere if users use a monitor with a resolution higher than Full HD. That is what various users claim. The WiFi connection works fine at lower resolutions.

When using a resolution of 2560×1440 pixels on a monitor, WiFi stops working immediately, no matter what output the user tries, developer Enrico Zini claims. The problem was also mentioned earlier in a topic on the Raspberry Pi forum. Several users confirm the problem.

Presumably the HDMI connection is causing interference. Hacker News users think it’s cvt-rb which, thanks to its resolution, ends up at a pixel clock around 2.4GHz, which could affect WiFi, which operates on the 2.4GHz band. Various users also claim that it also happens with last year’s MacBook Air when connecting a USB 3 dock. Raspberry Pi has not yet responded to the issue.